Heat exchanger



A. o. TADEWALD HEAT EXCHANGER Jan. 21, 1958 2 Sheets-Sheet 2 Filed Nov. 7, i955 INVENTOR.

ALBERT O. TADEWALD MVW United HEAT EXCHANGER Application November 7, 1955, Serial No. 545,187

2 Claims. (Cl. 257-26218) This invention relates to heat exchangers and particularly heat exchangers having tubes with fins secured to the outside of the tubes. One heat exchange fluid passes through the tubes and another heat exchange fluid flows over the outside of the tubes between the fins.

It is an object of this invention to provide a heat exchanger which is easily assembled from elements which are simple to manufacture.

It is another object of the invention to provide a continuous corrugated fin which can be fitted to a curved tube.

It is still another object of the invention to provide a corrugated fin element with tube receiving recesses in which the material is overlapped upon itself.

Other objects and advantages of my invention will become apparent as the specification proceeds to describe the invention with reference to the accompanying drawings in which:

Figure 1 is a plan view of the heat exchanger of this invention;

Figure 2 is an end view of the heat exchanger;

Figure 3 is a sectional view taken on line 3-3 of Figure 1;

Figure 4 is a perspective view of a fin element sectioned in a plane normal to the fin element;

Figure 5 is a view of a fin and tube section taken generally on line 5-5 of Figure 3;

Figure 6 is a view of a fin and tube section taken on line 66 of Figure 5;

Figure 7 is a view of a fin and tube section taken from line 7--7 of Figure 6; and

Figure 8 is an end view of a fin and tube section.

Referring now to Figures 1 and 2 of the drawings, the heat exchanger has a supply header 10 and a discharge header 12. Arcuate tubes 14 are brazed in fluid communication with supply header 10 and with U-bends 16. Arcuate tubes 18 are brazed in fluid communication with discharge header i2 and with U-bends 16.

Corrugated has 20 are brazed to the tubes 14 and 18. The corrugated fins 20 have tube receiving recesses 22 extending into one face of the fin sheet. The excess material iron: the recess forming operation is folded upon itse t to form laminae 24, 26, 28, 30, and 32.

Laminae 2.5, 28, and 32 have a maximum depth at the transverse central plane of the recess and the depth decreases according to the distance from the transverse central plane.

Duct sheets 3-4, 35, and 33 are brazed to the fins 20. Tube support sheets 40 have holes through which tubes 14 and 18 extend. Tube support sheets 40 are brazed to tubes 14 and 13 and to duct sheets 34, 36, and 38.

Duct sheets 34, 36, and 38 together with tube sheets 40 form a duct for conducting a second heat exchange through the fins 20 and over the tubes 14.

The method used in producing the heat exchanger from the component parts will now be described. My preferred rates Patent 0 .latented Jan. 21, 1958 method of welding the parts together involves providing a thin coating of lower melting alloy on the surfaces of the parts and raising the temperature of the assembled parts to the melting point of the surface material but below the melting point of the base material. It should be understood that it is only necessary that one of two contacting surfaces need have the welding coating. I prefer to heat the assembly to welding temperature while submerged in a flux bath. Instead of heating the assem bly in a flux bath, it may, if desired, be heated to welding temperature in a controlled atmosphere furnace.

I prefer to make the parts of aluminum. The tubes 14 and 18 are first formed to arcuate shape, the fins 20 are assembled to the tubes 20 and the duct sheets 34, 36 and 38 are also assembled in place. The fins 20 have a lower melting alloy on both surfaces to make a weld between the fins and the tubes and between the fins and the duct sheets.

While the apparatus disclosed and described herein con stitutes a preferred form of the invention, yet it will be understood that the apparatus is capable of alteration without departing from the spirit of the invention, and that all modifications that fall within the scope of the appended claims are intended to be included herein.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A heat exchanger comprising a supply header and a discharge header, conduit extending in fluid communication with said supply header and said discharge header for conducting heat exchange fluid from said supply header to said discharge header, corrugated fins of sheet material having crests and troughs, recesses in the crests of said corrugations, said recesses being shaped to fit the outside surface of the conduit, a double course of fin material extending under each of said recesses from one side of said recess, a second double course of fin material extending under each of said recesses from the other side of said recess and means integrally joining said fins to said conduit at said recesses.

2. A heat exchanger comprising a conduit for conducting a first heat exchange fluid, a corrugated fin of sheet material having crests and troughs with the crests lying in a first surface and the troughs lying in a second surface which is substantially parallel to said first surface, the crests of said corrugated fin having aligned recesses forming a groove extending transverse to the longitudinal axes of the corrugations of said corrugated fin, a first double course of fin material extending under each of said recesses from one side of said recesses, a second double course of fin material extending under each of said recesses from the other side of said recesses, said conduit being nested in said groove, means integrally joining said conduit to said corrugated fin at said recess, means integrally joining the courses of said first double course of fin material to each other and to said recesses, and means integrally joining the courses of said second double course of fin material to each other and to said first double course of tin material.

References Cited in the file of this patent UNITED STATES PATENTS 1,058,590 Hunker Apr. 8, 1913 1,102,810 Snyder July 7, 1914 1,970,105 Smith Aug. 14, 1934 2,035,403 Przyborowski Mar. 24, 1936 2,119,761 Wentworth June 7, 1938 2,261,579 Booth Nov. 4, 1941 FOREIGN PATENTS 723,398 Great Britain Feb. 9, 1955 

